Rory McIlroy broke a host of records to take a six-shot lead into round three of the US Open at Congressional.
McIlroy, 22, matched the biggest halfway lead in US Open history and posted the lowest 36-hole total with 66, 65 for 131 and 11 under.
He also became the first US Open player ever to reach 13 under but double-bogeyed the last via the water.
YE Yang was his only real rival but could get no closer than six strokes and carded 69 to end five under.
Sergio Garcia (71), Robert Garrigus (70), Brandt Snedeker (70), Zach Johnson (69) and Matt Kuchar (68) all finished two under.
Phil Mickelson bounced back with a 69 to climb to one over alongside Lee Westwood (68), while defending champion Graeme McDowell (74) ended two over and world number one Luke Donald (72) made the cut with no room to spare at four over.
The year's second major is traditionally set up to discourage low scoring and only 14 of the 156-man field finished under par on the second longest course in US Open history.
But Northern Ireland's McIlroy, who led by three shots after an opening 65, produced another Maryland masterclass and was back in the clubhouse with an eight-shot advantage before second-placed man Yang had started his second round.
McIlroy birdied the fourth and sixth and then saw his 113-yard pitch to the eighth spin back from the rear of the green and drop for an eagle as playing partner Mickelson applauded.
The shot gave McIlroy a seven-stroke lead and made him the first player in the 111-year history of the US Open to reach 10 under during the second round.
Another birdie followed at the 467-yard 14th and he watched in agony as his eagle putt on 16 stayed out by a hair's breadth.
The ensuing birdie took him alongside Woods (2000) and Gil Morgan (1992) as the only man ever to reach 12 under in a US Open, but he took the record on his own at the 17th with another birdie.
But McIlroy caught the left rough with his drive on 18 and his second found the water short of the green en route to a double-bogey six.
A par would have broken Nick Faldo's record for the lowest halfway total in major history (130 in the 1992 Open at Muirfield). He did, though, break the US Open record for lowest 36-hole total of 132 set in 2009 by American Ricky Barnes.
The two dropped shots on 18 were the first strokes McIlroy had leaked all tournament. In 36 holes he has hit 32 greens in regulation and 20 of 28 fairways.
"It's mostly to do with my attitude more than anything else," said McIlroy. "I did a piece after Augusta where I said I needed to be a little more cocky, a little more arrogant on the golf course, and think a little bit more about myself, which I've tried to incorporate a little bit, just on the golf course.
"Par golf now could be good enough but I've got to go out there and play the way I have been playing and make very committed swings and play aggressively to the targets that I pick."
Yang briefly threatened to eat into McIlroy's lead after picking up two shots in three holes to reach the turn five under, but a 42-minute delay for lightning in the area derailed his charge and he swapped two birdies with two bogeys coming home.
Twenty one players were left to finish their first rounds on Saturday after sunset halted play following the weather delay.
McIlroy's leading margin equalled Tiger Woods's mark set at the 2000 US Open when he went on to win by a record 15 shots.
Should McIlroy triumph, he would be a few months younger than Jack Nicklaus was when he lifted the first of his 18 majors in 1962.
He would also be the youngest US Open champion since another legend of golf - amateur Bobby Jones - in 1923.
"I know better than anyone else at the minute that things can turn very strange and weird things can happen," said McIlroy who blew a four-shot lead going into the final round of the Masters and followed an opening 63 with a second-round 80 at the Open last year.
"I've got to keep focused and keep mentally strong for these next 36 holes."
Robert Rock reached halfway as the leading Englishman after adding a 71 to his opening 70 for one under despite not arriving in time for a practice round after being delayed in the UK with visa problems.
The 41-year-old Mickelson, a five-time US Open runner-up, had a day to forget with his driver on Thursday but found more control to edge back before matching McIlroy by double-bogeying 18.
"He's striking it flawlessly and putted great on the greens," said Mickelson of playing partner McIlroy. "His first two rounds were very impressive."
Westwood bettered his opening round by seven shots, while Donald climbed to level par after four birdies on his front nine but gave all four back after the delay to flirt with the cut.
"The attitude I'm going to go with over the next couple of days is to try and get past whoever is in the second spot - and we'll see what Rory does," said Westwood. "He's had leads before."
Third-ranked Martin Kaymer, playing alongside Donald and Westwood, ended two over after a 74.
The four-over cut left Stephen Gallacher, Hunter Mahan, Stewart Cink, Martin Laird, Rickie Fowler, Justin Rose, Paul Casey (all +5), Ian Poulter and Ernie Els (+6) and Miguel Angel Jimenez (+8) all with a free weekend.